Index: lib/MC/MCStreamer.cpp
===================================================================
--- lib/MC/MCStreamer.cpp
+++ lib/MC/MCStreamer.cpp
@@ -881,9 +881,8 @@
 /// the specified string in the output .s file.  This capability is
 /// indicated by the hasRawTextSupport() predicate.
 void MCStreamer::EmitRawTextImpl(StringRef String) {
-  errs() << "EmitRawText called on an MCStreamer that doesn't support it, "
-  " something must not be fully mc'ized\n";
-  abort();
+  llvm_unreachable(
+    "EmitRawText called on an MCStreamer that doesn't support it");
 }
 
 void MCStreamer::EmitRawText(const Twine &T) {